JP3182192B2 - Method and apparatus for producing monomer droplets - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing monomer droplets used in an apparatus for producing a granular polymer from a monomer.
The present invention relates to a method and an apparatus for producing monomer droplets that can be safely operated without fear of ignition or explosion.

[0002]

2. Description of the Related Art Conventionally, there are various types of apparatuses for producing a granular polymer, but a production apparatus comprising a monomer droplet generating apparatus equipped with a vibrator and a polymerization apparatus has a uniform particle size. It is most excellent in that a polymer having a diameter can be obtained.

In this manufacturing apparatus, a monomer droplet generating apparatus ejects a monomer phase from pores to form a laminar monomer ejection stream, and applies a certain vibration to the monomer ejection stream by a vibrator. Then, a monomer is polymerized while maintaining the particle size distribution, thereby producing a granular polymer having a uniform particle size. In addition, a capillary, an orifice,
Nozzles, capillaries, and the like are used, and a mechanical, hydraulic, motor vibration type, electric, etc. vibrator is used as the vibrator (Japanese Patent Application Laid-Open Nos. Sho 57-73002 and 57-73). 10
2905, JP-A-57-167301, JP-A-57-167301
-205402, JP-A-61-115902).

[0004]

By the way, since monomers are usually flammable, ignitable or explosive, sufficient care and precautions are required for handling. In particular, when a polymer having a uniform particle size is to be industrially manufactured using a monomer droplet generating apparatus equipped with a shaker, a large amount of monomer is used, and a spark generated by the shaker is required. Is a source of ignition, so there is a high risk of ignition, ignition or explosion. However, in the monomer droplet generating apparatus used in the above-mentioned conventional manufacturing apparatus, there is no known method in which sufficient safety measures have been taken against ignition, ignition, or explosion of the monomer, and the safety is lacking. Was. It is an object of the present invention to improve the conventional monomer droplet apparatus to eliminate such problems.

[0005]

Means for Solving the Problems In order to achieve the above object, a first aspect of the present invention is to apply a vibration to a monomer ejection flow formed by ejecting a monomer from a fine hole by a vibrator to form a monomer droplet. At the time of generation, the vibrator is encased by a shielding means via a vibration isolating means for isolating the vibrating machine from external vibration and is shielded from the outside, and the inside of the shielding means is ventilated by a gas which is free from ignition, ignition and explosion. The second aspect of the present invention relates to a method for producing monomer droplets characterized by cooling. The second aspect of the present invention is a means for ejecting a monomer from pores to form a monomer ejection flow, and applying a vibration to the monomer ejection flow to form a monomer droplet. In the monomer droplet generating apparatus provided with a vibrator to be provided, while the vibrator is installed in a shielding box via a vibration isolating member that isolates the vibration from external vibration, a ventilation line and a pressure control device are provided in the shielding box. With Was monomer droplets generator apparatus characterized by the, those whose content respectively.

[0006]

In the method and the apparatus for producing monomer droplets having the above-mentioned construction, the vibrator is covered by the shielding means via the vibration isolating means for isolating it from the external vibration, and is shielded from the outside. Ventilation cooling with gas that is not likely to cause ignition, ignition or explosion prevents monomer gas or liquid from approaching the shaker, and also cools the shaker to reduce heat generation and sparks. Prevent from becoming a source of ignition. Therefore, there is no risk of ignition, ignition or explosion of the monomer, and the operation can be performed safely.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the apparatus used in the present invention will be described below with reference to FIGS. As shown in FIG. 1, the monomer droplet generating apparatus according to the present embodiment includes a monomer storage tank 1 connected to a monomer supply line 2, a vibration unit 3, and a pressure pulse control device 4. And is attached to the installation surface 5.

[0008] The monomer storage tank 1 is a container having an open top, and has a large number of monomer ejection pores 6 at the bottom. The pores 6 are orifices, and at least 300 or more, preferably 1000 or more are provided in the case of industrial production.

The monomer supply line 2 is connected to the side wall of the monomer storage tank 1 and has a flow control device 7 in the middle.
The flow rate adjusting device 7 adjusts the monomer supply amount so that the monomer jet 8 jetting out of the fine holes 6 becomes laminar.

The vibrating means 3 accommodates the vibrator 9 in a shielding box 21 which will be described later, and connects a vibrating plate 10 provided below the vibrator 9 to the top of the monomer storage tank 1 via a vibration isolating member 11. In addition to being connected to the opening, the upper part of the vibrator 9 is attached to the shielding box 21 via the vibration isolating member 12, and the shielding box 21 is fixed to the installation surface 5. As the vibrator 9, an electrodynamic type vibrator is used. This electro-dynamic type vibrator vibrates the vibrating bar up and down by passing an alternating current through the electric coil. It generates a constant and accurate sine wave and exhibits a large vibrating force. And suitable for producing monomer droplets at an industrial production level. The vibration plate 10 transmits the vibration of the vibrator 9 to the monomer 16 in the monomer storage tank 1 as a pressure pulse. Anti-vibration member 11
Is for preventing the vibration of the vibration plate 10 from being directly transmitted to the side wall of the monomer storage tank 1, and is made of a diaphragm, a bellows or the like, and a metal bellows such as stainless steel is particularly preferable. The vibration isolating member 12 isolates the vibration exciter 9 from the outside, and uses an ordinary air cushion or the like.

The pressure pulse controller 4 includes a pressure sensor 13 provided at the bottom of the monomer storage tank 1 and a charge amplifier 14 connected between the pressure sensor 13 and the vibrator 9.
A pressure pulse propagating in the monomer 16 in the monomer storage tank 1 is detected by the pressure sensor 13, and the output thereof is sent to the shaker controller 15 via the charge amplifier 14. By feeding back and adjusting the vibration acceleration of the vibrator 9 to adjust the pressure pulse to a set value, the particle diameter of the monomer droplet 17 is made uniform.

The vibrating means 3 has an explosion-proof structure as shown in FIG. 2, which is a feature of the present invention.
That is, the vibration exciter 9 is covered by the shielding box 21 and is shielded from the outside, and the ventilation lines 22 and 23 and the pressure control device 24 are connected to the shielding box 21.

The shielding box 21 is a metal box,
And supports the upper portion of the vibrator 9 via a vibration isolator 25, and is connected to the diaphragm 10 of the vibrator 9 via a vibration isolator 25.
It is fixed to the installation surface 5. The inside of the shielding box 21 communicates with the inside of the shaker 9 via the air outlet 26 of the shaker 9. The anti-vibration member 25 is a non-combustible diaphragm made of rubber or the like, and maintains airtightness between the diaphragm 10 and the shielding box 21 and isolates the diaphragm 10 from external vibration.

The ventilation line 22 is a vibration-proof air supply line composed of a nonflammable flexible hose or the like.
1 is connected to an air inlet 28 of the vibrator 9 through a flexible tube 27, has a blower 29 in the middle, and the other end is open to the outside atmosphere. The flexible tube 27 is made of a nonflammable rubber tube or the like, and the blower 29 is installed outdoors. The ventilation line 23 is a vibration-proof exhaust line composed of a nonflammable flexible hose or the like.
The other end is open to the outside atmosphere.

The pressure control device 24 comprises a pressure sensor 30 provided on the side wall of the shielding box 21 and a pressure controller 31 connected between the pressure sensor 30 and the shaker controller 15. 30 detects the pressure in the shielding box 21, and the pressure controller 31 permits the operation of the vibrator 9 only when the detected pressure is equal to or higher than a set pressure set about 100 mm higher than the pressure of the factory atmosphere by a water column. Act like so. This prevents the monomer gas in the factory from flowing into the shielding box 21 during the operation of the vibrator 9.

In order to industrially produce monomer droplets by the monomer droplet producing apparatus having the above-mentioned configuration, first, the blower 2
By operating the gas turbine 9, gas 32 having no risk of ignition, ignition and explosion is injected into the vibrator 9 from the air inlet 28 of the vibrator 9 through the ventilation line 22. This gas 32 is outdoor normal temperature air, and the content of the flammable gas must be 1/4 or less (usually 1 ppm or less) of the lower limit of explosion of the flammable gas. The gas 32 exits the air outlet 26 of the vibrator 9, fills the shielding box 21, pressurizes the inside of the shielding box 21, and is discharged outside through the ventilation line 23. The pressure sensor 30 detects the pressure in the shielding box 21, and when the detected pressure becomes equal to or higher than the set pressure, the pressure controller 31 operates to make the vibrator 9 operable.

Next, the monomer 16 is charged into the monomer storage tank 1 from the monomer supply line 2 while operating the vibrator 9. The monomer 16 is made of a vinyl monomer such as styrene, α-methylstyrene, divinylbenzene, acrylonitrile, acrylate, methacrylate or the like, or a mixture thereof. Monomer jet 8 in laminar flow
It gushes out. On the other hand, the vibration of the vibration plate 10 of the vibrator 9 propagates as a pressure pulse in the monomer 16 in the monomer storage tank 1, and forms a surface wave on the surface of the liquid column of the monomer jet stream 8, thereby causing the monomer liquid to flow. A drop 17 is formed. At this time, the pressure sensor 13 detects the pressure pulse, and outputs the output through the charge amplifier 14 to the shaker controller 1.
Feedback to 5 The shaker controller 15
The particle size of the monomer droplets 17 is made uniform by adjusting the vibration acceleration of the vibrator 9 and adjusting the pressure pulse to a preset value set in advance according to the ejection speed of the monomer ejection flow 8. Here, the uniform particle size means that the monomer droplet group has a weight of the entire droplet group within a range of ± 10% of the average particle size.
% (Preferably 90%).

During the operation of the vibrator 9, the gas 3
2 cools the inside of the shielding box 21 and the vibrator 9 while keeping the pressure higher than the pressure of the factory atmosphere. For this reason, it is possible to prevent gas or liquid of the monomer from entering the shielding box 21 or to prevent a heat-generating portion, a spark, or the like of the vibrator 9 from becoming an ignition source, and eliminate danger of ignition, ignition, or explosion of the monomer.

In this embodiment, the inside of the vibrator 9 and the shielding box 21 is cooled by ventilation with the gas 32. However, in another embodiment, when the vibrator 9 is relatively small, the gas 32 is cooled.
May be directly pressed into the shielding box 21 and the vibrator 9 may be cooled by natural convection of the gas 32 in the shielding box 21.

Hereinafter, the results of a monomer droplet formation test performed using the apparatus shown in FIG. 1 will be described. In the test, styrene droplets were formed in a 250 ppm aqueous solution of PVA (polyvinyl alcohol) under the following conditions. Number of orifice holes 1628 Orifice diameter 56cm Diaphragm diameter 18cm Styrene-filled chamber angle 40 ° Styrene jet velocity 180cm / sec Pressure pulse frequency 800Hz Pressure pulse strength 2mbar Exciter (dynamic type) Exciting force of 50kgf Internal pressure of shielding means 100mm water column

Since the specific gravity of the styrene droplet is smaller than that of the PVA aqueous solution, the apparatus shown in FIG. 1 was installed on the floor, a PVA aqueous solution tank was mounted on the orifice, and styrene was jetted into the PVA aqueous solution. The PVA aqueous solution was supplied to the PVA aqueous solution tank at the same flow rate as the supply amount of styrene, and overflowed from the upper portion of the PVA aqueous solution tank. Styrene and PV
After supplying the aqueous solution A and stabilizing the system, a slurry in which styrene droplets were dispersed in the aqueous PVA solution was recovered from the upper portion of the PVA aqueous solution tank. During the test, the device operated safely and there was no risk of styrene ignition, ignition or explosion.
In addition, the collected slurry was photographed with a stereoscopic microscope and subjected to image processing to measure the particle size distribution of styrene droplets.
4.4% was contained within the particle size range of 0.423-0.464 mm.

For comparison, when the styrene droplets were produced in the same manner as above with the shielding means removed, the particle diameter of the styrene droplets was also uniform, but the styrene was prepared in the room. The gas was filled in the room, and the styrene gas concentration around the apparatus was as high as 10 ppm. For this reason, in the case of industrial-scale operation, if a large amount of styrene leaks due to equipment malfunction, etc., the styrene gas concentration will increase significantly, and the risk of ignition, ignition, or explosion of the styrene gas by the vibrator is foreseen. Was done.

[0023]

As described above, according to the present invention, the vibrator is covered by the shielding means and is shielded from the outside, and at least the inside of the shielding means is ventilated and cooled by a gas which is free from ignition, ignition and explosion. With this configuration, the monomer gas or liquid is prevented from approaching the shaker, and the shaker is cooled to prevent the heat-generating portion, sparks, and the like from becoming a source of ignition. Therefore, the apparatus for producing a granular polymer using the apparatus for producing monomer droplets of the present invention can safely operate without fear of ignition, ignition or explosion of the monomer.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a monomer droplet generating apparatus showing one embodiment of the present invention.

FIG. 2 is an enlarged explanatory view of a vibration means in FIG. 1;

[Explanation of symbols]

 6 Pores 8 Monomer jet 9 Shaker 16 Monomer 17 Monomer droplet 21 Shielding box 32 Gas (for ventilation cooling)

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-61-115902 (JP, A) JP-A-2-305802 (JP, A) JP-A-2-199137 (JP, A) JP-A 57-115 102905 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C08F 2/01

Claims (3)

(57) [Claims] 1. A vibration damping means for isolating the vibrator from external vibration when generating a monomer droplet by applying vibration to the monomer jet flow formed by jetting the monomer from the pores by a vibrator. A method for producing monomer droplets, characterized in that the monomer droplet is encapsulated by a shielding means and is shielded from the outside, and the inside of the shielding means is cooled by ventilation with a gas which does not cause ignition, ignition or explosion. 2. The method according to claim 1, wherein the pressure inside the shielding means is set higher than the pressure outside. 3. A monomer droplet generating apparatus comprising: means for ejecting a monomer from a fine hole to form a monomer ejection flow; and a vibrator for applying vibration to the monomer ejection flow to form a monomer droplet. While installing in a shielding box via a vibration isolator that isolates the shaker from external vibrations,
A monomer droplet generation device, wherein a ventilation line and a pressure control device are attached to the shielding box.